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This is why it is generally recommended that subroutines should use return with no arguments when the intent is to return a false value --- in scalar context it returns undef, in list context it returns an empty list.

It doe not return undef in scalar context, it still returns the empty list, but that will evaluate to undef. If a sub always returns a single element, it makes no sense to use return without arguments, and return undef is much more explicitly self documenting.

If your sub normally returns a scalar, use an explicit return undef;.
If your sub normally returns a list with more than one element, use an explicit return ();.
If your sub is polymorphic, return without arguments. Or do so explicitly: return wantarray ? () : undef;.

- Yes, I reinvent wheels.
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In reply to Re: Re: undef'ing @arrays caveat by Juerd
in thread undef'ing @arrays caveat by vladb

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